JP2017102187A - Electrophoretic display device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve smooth movement of migration particles in a region (cell) segmented by partition walls formed between two substrates.SOLUTION: An electrophoretic display device is provided, in which partition walls are disposed between a first substrate and a second substrate; a dispersion liquid is disposed in a region segmented by the partition walls; the dispersion liquid comprises a dispersion medium and migration particles; in one unit of the region, a face parallel to the display screen has a rotational asymmetric shape which does not coincide with itself when rotated by a given angle of larger than 0° and smaller than 360°; a face of the partition wall on the region side has an inclination portion inclined with respect to the normal direction of the first substrate; and such a configuration is excluded that all faces of the partition walls on the above region side, corresponding to a plurality of side lines formed by the intersection between the faces of the partition walls on the above region side and a face of the region on the first substrate side, have inclination portions in the same inclination direction with the same inclination angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrophoretic display device and an electronic apparatus.

  A display device (electrophoretic display device) using electrophoresis is known. The electrophoretic display device has an electrophoretic layer between two substrates facing each other (herein, the pixel substrate and the counter substrate), and the dispersion medium (solvent) exists in the electrophoretic layer. Display is performed by moving charged particles that migrate (hereinafter referred to as migrating particles) by an electric field. The electric field is generated by applying a potential difference between the two substrates. In addition, one of the two substrates (the surface of the counter substrate) serves as a display surface. The electrophoretic display device can be applied to electronic devices such as electronic paper. The electrophoretic display device is also referred to as EPD (Electrophoretic Display).

  By providing a partition between the two substrates, the electrophoretic layer is partitioned into a plurality of regions (cells). Conventionally, as an example, the partition wall is formed in the normal direction with respect to the display surface (see Patent Document 1). As another example, a partition wall having different widths may be provided on one substrate side and the other substrate side. In this case, the partition wall has a trapezoidal surface.

  In addition, the shape of the display surface of one region (cell) formed by the barrier ribs (hereinafter also referred to as the barrier rib display surface shape) is conventionally a rotationally symmetric shape such as a square or a regular hexagon. It has become.

Here, in this specification, a rotationally symmetric shape is a shape in which there is an angle that is the same shape when the shape is rotated by an angle of any angle greater than 0 ° and less than 360 °. Say. In this case, the center point of rotation may be an arbitrary point, and as an example, a centroid may be used. The central axis of rotation is, for example, an arbitrary axis parallel to the normal to the display surface. In this specification, a shape that is not rotationally symmetric is referred to as a rotationally asymmetric shape.
Moreover, in this specification, a line symmetrical shape means the shape in which the straight line which becomes symmetrical with respect to the straight line exists among arbitrary straight lines. In this specification, a shape that is not line-symmetric is called a line-asymmetric shape.

When a potential difference is applied between two substrates when rewriting an image to be displayed, an electric field is generated in the normal direction of the two substrates, and the migrating particles pass through the dispersion medium in the normal direction ( Migrating in the electric field direction). For example, the color of the migrating particles that have moved to the transparent counter substrate side becomes the display color. As an example, when the first type of migrating particles (for example, migrating particles corresponding to white) and the second type of migrating particles (for example, migrating particles corresponding to black) are present in the dispersion medium, they are present on the counter substrate side. The one type of migrating particles descends to the pixel substrate side, and the other type of migrating particles present on the pixel substrate side rises to the counter substrate side.
In this case, when rewriting the image to be displayed, each migrating particle will collide by moving in the reverse direction in the normal direction, and the movement direction of each migrating particle is not fixed due to the influence of the dispersion medium. In some cases, the optical response was delayed due to the situation.

FIG. 15 is a cross-sectional view showing a schematic configuration of an electrophoretic display device 1001 in which the partition surface has a square display surface shape and the partition walls are formed in the normal direction to the substrate.
In the electrophoretic display device 1001, partition walls 1013 and 1014 are formed between the pixel substrate portion 1011 and the counter substrate portion 1012. The pixel substrate portion 1011 schematically shows a pixel substrate and a pixel electrode. The counter substrate portion 1012 is shown schematically but includes a counter substrate and a counter electrode. In addition, a dispersion medium and electrophoretic particles are arranged (for example, enclosed) in a region (cell) partitioned by partition walls 1013 and 1014 formed between the pixel substrate portion 1011 and the counter substrate portion 1012.
FIG. 15 shows an example of the flow of migrating particles (for example, the first type of migrating particles) in the cell. In the example of FIG. 15, the generation of a flow (downflow) in the direction from the upper (vertical upper) substrate (counter substrate 1012) to the lower (vertical lower) substrate (pixel substrate 1011) is not determined, and the upward flow And turbulent flow.

Here, the point that the response time until the display color of the electrophoretic display device is displayed is long will be described in more detail.
According to the study of the present inventor, when a certain number of electrophoretic particles migrate to the electrophoretic layer, the dispersion medium also drags and flows. Then, for example, when the dispersion medium flows from the pixel substrate toward the counter substrate, molecules of the dispersion medium in the vicinity of the counter substrate are excluded.
However, since the cell structure and the electric field are symmetric, for example, the forces acting on the dispersion media in the vicinity of the counter substrate antagonize each other, so that a situation in which the flow does not progress occurs. And if the equilibrium is broken for some reason, the indefinite turbulence is generated for the first time.

The migration speed of the migrating particles is limited to the final speed by the viscosity of the dispersion medium. The final velocity is a relative velocity with respect to the dispersion medium around the migrating particles. For example, when the dispersion medium is flowing upward, the moving speed of the migrating particles in the upward direction is a speed obtained by adding the flow speed of the dispersion medium to the final speed.
That is, for example, when the rising electrophoretic particles are in the rising dispersion medium, the moving speed of the electrophoretic particles is increased, and when the dispersing medium does not flow, the moving speed of the electrophoretic particles is the final speed, and the rising electrophoretic particles In the dispersion medium in which descent occurs, the moving speed of the migrating particles becomes slow. The same applies to the migrating particles that descend.
In this way, in a situation until the symmetry breaking occurs, or in a situation where turbulence occurs and the rising or lowering of the dispersion medium cannot be determined, smooth movement of the migrating particles is prevented. This is a factor that slows down the optical response.

JP 2011-237706 A

  Conventionally, in an electrophoretic display device, smooth movement of electrophoretic particles may not be realized in a region (cell) partitioned by a partition formed between two substrates. As a result, smooth image rewriting may not be realized.

  The present invention has been made in view of the above points, and can achieve smooth movement of electrophoretic particles in a region (cell) partitioned by a partition formed between two substrates. An object is to provide an electrophoretic display device and an electronic apparatus.

In order to solve at least one of the above problems, one embodiment of the present invention provides a partition wall between a first substrate and a second substrate, disperses a dispersion in a region partitioned by the partition wall, and The dispersion includes a dispersion medium and electrophoretic particles, and the shape of a plane parallel to the display surface of one unit of the region is rotationally asymmetric that does not coincide with rotation at any angle greater than 0 ° and less than 360 °. And the surface of the partition on the side of the region has an inclined portion that is inclined with respect to the normal direction of the first substrate, and the surface of the partition on the side of the region and the first surface The surface on the side of the region of the partition corresponding to all of the plurality of sides formed by the intersecting line with the surface on the one substrate side has the inclined portions having the same inclination direction and the same inclination angle. It is an electrophoretic display device that is not configured.
With this configuration, in the electrophoretic display device, the shape of the surface parallel to the display surface of one unit region (cell) and the inclined portion of the partition promote the smooth movement of the electrophoretic particles in the region (cell). Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

According to one embodiment of the present invention, in the electrophoretic display device, the surface of the partition on the side of the region is symmetric when rotated at two or more different angles with respect to the normal axis of the first substrate. A configuration that does not have the property may be used.
With this configuration, in the electrophoretic display device, the inclined portion facilitates smooth movement of the electrophoretic particles in the region (cell) due to the absence of the symmetry. Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

According to one embodiment of the present invention, in the electrophoretic display device, only one of a plurality of sides formed by a line of intersection between the surface on the region side of the partition and the surface on the first substrate side is supported. The structure by which the surface by the side of the said area | region of the said partition has the said inclination part may be used.
With this configuration, in the electrophoretic display device, the inclined portion facilitates smooth movement of the electrophoretic particles in the region (cell). Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

In one embodiment of the present invention, in the electrophoretic display device, a configuration in which the shape of the surface of the unit of the region parallel to the display surface is a shape having four or more vertices may be used.
With this configuration, the electrophoretic display device facilitates the smooth movement of the electrophoretic particles in the region (cell) by the shape of the surface parallel to the display surface of the one unit region. Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

In one embodiment of the present invention, in the electrophoretic display device, a shape of a surface parallel to the display surface of the region of the unit is a triangle, the shape is the rotationally asymmetric shape, and an arbitrary shape A configuration having a line asymmetric shape that is asymmetric with respect to the straight line may be used.
With this configuration, the electrophoretic display device facilitates the smooth movement of the electrophoretic particles in the region (cell) by the shape of the surface parallel to the display surface of the one unit region. Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

According to one embodiment of the present invention, in the electrophoretic display device, two of the plurality of sides that are parallel to each other among the plurality of sides formed by the surface of the partition and the surface of the first substrate are formed. The surface on the side of the region of the partition corresponding to the side of the side is configured so that both have the inclined portion, and the surface with respect to the plane parallel to the normal direction of the first substrate including each side A configuration that is not a configuration in which the inclination direction of the inclined portion is reversed and the inclination angle is the same may be used.
With this configuration, in the electrophoretic display device, the asymmetrical inclined portions in the partition walls corresponding to the two sides described above facilitate the smooth movement of the electrophoretic particles in the region (cell). Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

One embodiment of the present invention is the electrophoretic display device, in which the surface on the side of the region of the partition corresponding to two of the plurality of sides parallel to each other has both the inclined portions. A configuration in which the tilt direction and the tilt angle of the tilt portion with respect to a plane parallel to the normal direction of the first substrate including the respective sides is the same configuration may be used.
With this configuration, in the electrophoretic display device, the asymmetrical inclined portions in the partition walls corresponding to the two sides described above facilitate the smooth movement of the electrophoretic particles in the region (cell). Thereby, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

According to one embodiment of the present invention, in the electrophoretic display device, the surface on the region side of the partition wall corresponding to two of the plurality of sides parallel to each other is a plane. May be.
With this configuration, in the electrophoretic display device, the inner surface (surface on the region (cell) side) of the partition wall corresponding to the two sides described above is a flat surface. As a result, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates with a configuration that is easy to create. .

In one embodiment of the present invention, in the electrophoretic display device, a surface of the partition corresponding to two sides parallel to each other among the plurality of sides is a surface having a curved portion. A configuration may be used.
With this configuration, in the electrophoretic display device, the inner surface (surface on the region (cell) side) of the partition wall corresponding to the two sides described above is a surface having a curved portion. As a result, in the electrophoretic display device, it is possible to realize a smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates with a configuration that is easy to create. .

In order to solve at least one of the above problems, one embodiment of the present invention is an electronic device including the above electrophoretic display device.
With this configuration, in an electronic apparatus, in an electrophoretic display device, the shape of the surface parallel to the display surface of one unit region (cell) and the inclined portion of the partition wall move smoothly in the region (cell). Prompt. Thereby, in the electronic apparatus, in the electrophoretic display device, it is possible to realize the smooth movement of the electrophoretic particles in the region (cell) partitioned by the partition formed between the two substrates.

  As described above, according to the electrophoretic display device and the electronic apparatus according to the present invention, in the electrophoretic display device, the shape of the surface parallel to the display surface of one unit region (cell) and the inclined portion of the partition wall are regions. Promotes smooth movement of migrating particles in (cell). As a result, in the electrophoretic display device and electronic apparatus according to the present invention, the electrophoretic particles move smoothly in the region (cell) partitioned by the partition formed between the two substrates in the electrophoretic display device. Can be realized.

It is sectional drawing which shows the structural example (1-1 structural example) which concerns on the cross-sectional shape of the partition of an electrophoretic display device. It is a figure which shows the structural example (1-1 structural example) of the area | region (cell) for demonstrating the cross-sectional shape of the partition of an electrophoretic display device. It is sectional drawing which shows the schematic structural example (1-1st structural example) for demonstrating the effect of the cross-sectional shape of the partition of an electrophoretic display device. It is sectional drawing which shows the schematic structural example (1-2 structural example) for demonstrating the effect of the cross-sectional shape of the partition of an electrophoretic display apparatus. It is sectional drawing which shows the schematic structural example (1st-3 structural example) for demonstrating the effect of the cross-sectional shape of the partition of an electrophoretic display device. It is a figure which shows the structural example (2-1 structural example) which concerns on the display surface shape of the partition of an electrophoretic display device. It is a figure which shows the schematic structural example (2-1 structural example) for demonstrating the effect of the display surface shape of the partition of an electrophoretic display device. It is a figure which shows the structural example (2-2 structural example) which concerns on the display surface shape of the partition of an electrophoretic display device. It is a figure which shows the structural example (2-3 structural example) which concerns on the display surface shape of the partition of an electrophoretic display device. It is a figure which shows the structural example (2-4th structural example) which concerns on the display surface shape of the partition of an electrophoretic display device. It is a figure which shows the structural example of the area | region (cell) of the electrophoretic display device which concerns on one Embodiment (1st Embodiment) of this invention. It is a figure which shows the schematic structural example of the electronic device which concerns on one Embodiment (1st example of 2nd Embodiment) of this invention. It is a figure which shows the schematic structural example of the electronic device which concerns on one Embodiment (2nd example of 2nd Embodiment) of this invention. It is a figure which shows the schematic structural example of the electronic device which concerns on one Embodiment (3rd example of 2nd Embodiment) of this invention. It is sectional drawing which shows the schematic structure of the electrophoretic display device in which the display surface shape of a partition was a square, and the said partition was formed in the normal line direction with respect to the board | substrate.

Embodiments of the present invention will be described in detail with reference to the drawings.
Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be easily recognized.

(First embodiment)
In this embodiment, each of the cross-sectional shape and the display surface shape of the partition wall of the electrophoretic display device is a characteristic shape.
In the following, first, the cross-sectional shape of the partition wall of the electrophoretic display device will be described, then the display surface shape of the partition wall of the electrophoretic display device will be described, and then the cross-sectional shape and display surface shape of the partition wall of the electrophoretic display device The combination of will be described.

<Description of sectional shape of partition wall of electrophoretic display device>
With reference to FIGS. 1-5, the cross-sectional shape of the partition of an electrophoretic display device is demonstrated.
Here, in order to explain the configuration and effect of the cross-sectional shape of the partition wall of the electrophoretic display device, the display surface shape of the partition wall is assumed to be a shape having rotational symmetry (here, a square shape).
In the present embodiment, a case where an electric field (vertical electric field) is applied between the pixel substrate and the counter substrate of the electrophoretic display device is shown.

FIG. 1 is a cross-sectional view illustrating a configuration example (first configuration example) according to a cross-sectional shape of the partition walls 31 to 33 of the electrophoretic display device 11.
The electrophoretic display device 11 includes a pixel substrate unit 21, a counter substrate unit 22, partition walls 31, 32, 33, a dispersion medium 41, a plurality of first type particles (electrophoretic particles 42), and a plurality of second types. Provided with seed particles (electrophoretic particles 43). In this configuration example, the first type of migrating particles 42 are electrophoretic particles corresponding to negatively charged white, and the second type of migrating particles 43 are electrophoretic particles corresponding to positively charged black. In the present configuration example, these two types of migrating particles 42 and 43 are charged with opposite charges. The colors of the first type particles and the second type particles are not limited to this example.
The pixel substrate unit 21 includes a pixel substrate 61, a plurality of pixel electrodes 62, and an insulating layer 63.
The counter substrate unit 22 includes a counter substrate 71 and a counter electrode 72.

The pixel substrate 61 and the counter substrate 71 are disposed to face each other. The pixel substrate 61 and the counter substrate 71 are arranged in parallel to each other. In this configuration example, the pixel substrate 61 and the counter substrate 71 each have a plate shape.
On the pixel substrate 61, a pixel electrode 62 is formed for each of a plurality of pixels on the side facing the counter substrate 71, and an insulating layer 63 is further formed.
A counter electrode 72 is formed on the counter substrate 71 on the side facing the pixel substrate 61. In this configuration example, the counter electrode 72 is common to the plurality of pixel electrodes 62. As another configuration example, a counter electrode 72 divided for each of the plurality of pixel electrodes 62 may be provided.
A space sandwiched between the pixel substrate unit 21 and the counter substrate unit 22 is partitioned into a plurality of regions (cells) by a plurality of partition walls 31 to 33 provided between the pixel substrate unit 21 and the counter substrate unit 22. Has been. In each cell, a dispersion medium 41, a plurality of first-type migrating particles 42, and a plurality of second-type migrating particles 43 are arranged (for example, enclosed). A dispersion liquid is composed of the dispersion medium 41 and the electrophoretic particles 42 and 43. Each cell layer is an electrophoretic layer.

FIG. 2 is a diagram showing a configuration example (first configuration example) of regions (cells) for explaining the cross-sectional shapes of the partition walls 31 to 33 and 81 to 82 of the electrophoretic display device 11 shown in FIG. It is.
In this configuration example, for example, the internal space defined by the partition wall 31, the partition wall 32, the partition wall 81, the partition wall 82, the pixel substrate unit 21, and the counter substrate unit 22 is one cell. On the surface of the pixel substrate portion 21, a plurality of cells having the same shape are provided side by side in two directions (horizontal direction and vertical direction) orthogonal to each other. In this configuration example, one cell has a square shape (for example, a square or a rectangle) on the surface of the pixel substrate portion 21, and a square shape (for example, a square or a rectangle) on the surface of the counter substrate portion 22. Have.
Moreover, in this structural example, each partition 31-33, 81-82 has plate shape. In addition, the inner surfaces (surfaces facing the inside of the cells) of the partition walls 31 to 33 have the same inclination with respect to a surface that includes an intersection line between the inner surface and the pixel substrate unit 21 and is parallel to the normal direction of the pixel substrate unit 21. Inclined at the same inclination angle in the direction. Further, the inner surfaces (surfaces facing the inside of the cells) of the partition walls 81 to 82 are surfaces parallel to the normal direction of the pixel substrate portion 21.
In this configuration example, the surface of the pixel substrate 61, the surface of the pixel substrate portion 21 (in this embodiment, the surface of the insulating layer 63), the surface of the counter substrate 71, and the surface of the counter substrate portion 22 (in this embodiment). , The surfaces of the counter electrode 72) are parallel to each other.

  In this configuration example, the electrophoretic display device 11 displays an image on the counter substrate 71 side (the side opposite to the pixel substrate 61). A surface on the counter substrate 71 side is a display surface.

In the electrophoretic display device 11, a voltage is applied to each pixel electrode 62 by a drive unit (not shown) and a voltage is applied to the counter electrode 72, so that the pixel electrode 62 and the counter electrode are provided for each pixel electrode 62. 72 to control the potential difference. Then, an electric field is generated in the normal direction of the pixel substrate 61 due to the potential difference.
When the potential of the counter electrode 72 is higher than that of the pixel electrode 62, for example, the first type of migrating particles (negatively charged white particles) 42 move to the counter electrode 72 side, and the second type of migrating particles (positive). Charged black particles) 43 move to the pixel electrode 62 side. Therefore, white is displayed.
On the other hand, when the potential of the counter electrode 72 is lower than that of the pixel electrode 62, for example, the first type of migrating particles (negatively charged white particles) 42 move to the pixel electrode 62 side, and the second type of migrating particles. (Positively charged black particles) 43 move to the counter electrode 72 side. Therefore, black is displayed.

FIG. 3 is a cross-sectional view illustrating a schematic configuration example (1-1 configuration example) for explaining the effect of the cross-sectional shape of the partition walls 31 to 32 of the electrophoretic display device 11.
Here, FIG. 3 is a schematic cross-sectional view of the same electrophoretic display device 11 as in FIG. In FIG. 3, the horizontal direction is enlarged to make the image of the flow of the dispersion easier to see.
1 and 3 are cross-sectional views of the cells partitioned by the partition wall 31, the partition wall 32, and the other partition walls 81 and 82, in which the partition wall 31 and the partition wall 32 facing each other are viewed from the side. Further, in FIG. 3, an image of the flow of the dispersion is indicated by arrows.

  In the cross-sectional views of FIGS. 1 and 3, the partition wall 31 and the partition wall 32 are inclined at the same inclination angle in the same inclination direction with respect to the normal direction of the surface of the pixel substrate portion 21 (normal direction of the surface of the pixel substrate 61). Has been formed.

  In the configuration of the partition walls 31 and 32, taking the cross-sectional view of FIG. 3 as an example, in the electrophoretic layer, the dispersion medium 41, the first type of migrating particles 42, and the second type of migrating particles 43 are unidirectional. A flow of rotation immediately occurs and rectifies. In the example of FIG. 3, the flow of the rotation in one direction is an upward flow from the bottom to the top on the partition wall 31 side, and a flow from the left to the right on the surface side of the counter electrode 72. On the side, there is a downward flow from top to bottom.

Specifically, when the migrating particles (here, the migrating particles 42 or the migrating particles 43) migrate upward, the dispersion medium 41 also flows upward. However, since the partition walls 31 and 32 are inclined, the dispersion medium 41 You will have a lateral speed. For this reason, when the electrophoretic display device 11 is viewed in cross section as shown in FIG. 3, when an electric field is applied between the pixel electrode 62 and the counter electrode 72, the dispersion medium 41 does not cause force competition. Immediately flows so as to rotate smoothly. Therefore, the migrating particles that rise in the ascending dispersion medium 41 (in other words, the migrating particles that raise the dispersion medium 41) rise quickly, and the response speed is improved.
Here, the inclination angles of the partition walls 31 and 32 may be arbitrary. However, if the inclination angle is too large, the speed of the dispersion medium 41 and the migrating particles 42 and 43 in the normal direction of the pixel substrate portion 21 is decreased. In some cases, it may be preferable.
Even when two or more types of migrating particles 42 and 43 having different polarities (charge polarities) are present, each type of migrating particles 42 and 43 has different mobility, concentration, etc. A similar effect is obtained for determining flow.

  As described above, in this configuration example, the partition walls 31 to 33 and 81 to 82 are provided between the pair of substrates (the pixel substrate 61 and the counter substrate 71), and the region is defined by the partition walls 31 to 33 and 81 to 82. In the electrophoretic display device 11 in which the dispersion liquid is disposed in the (cell), the dispersion liquid includes the dispersion medium 41 and the electrophoretic particles 42 and 43, and the partition walls 31 to 33 have the same inclination direction with respect to the normal direction of the substrate. It is inclined to. In this configuration example, the partition walls 31 to 33 are inclined at the same inclination angle.

In the electrophoretic display device 11 according to this configuration example, when the electrophoretic particles 42 and 43 are moved in the vertical direction due to the inclination of the partition walls 31 to 33, the electrophoretic particles 42 and 43 or the dispersion medium 41 that migrate in the vertical direction are used. The electrophoretic particles 42 and 43 or the dispersion medium 41 can be moved in the lateral direction with a lateral velocity. Thereby, the flow direction of the dispersion liquid (flow direction of the dispersion medium 41) arranged in the cells inside the partition walls 31 to 33 and 81 to 82 is applied to the pixel electrode 62 at the time of image rewriting (for example, for each pixel). In the direction of flow (rectification) that rotates and moves in one direction. Therefore, for example, it is possible to improve the speed of the optical response compared to the conventional case, and it is possible to speed up the switching of the displayed image.
As described above, in the electrophoretic display device 11 according to this configuration example, the electrophoretic particles 42 and 43 in the region (cell) partitioned by the partition walls 31 to 33 and 81 to 82 formed between the two substrates. Smooth movement can be realized. As a result, smooth image rewriting can be realized.

FIG. 4 is a cross-sectional view illustrating a schematic configuration example (1-2 configuration example) for explaining the effect of the cross-sectional shape of the partition walls 113 to 114 of the electrophoretic display device 101.
The electrophoretic display device 101 includes a pixel substrate unit 111, a counter substrate unit 112, and partition walls 113 to 114.
Here, like FIG. 3, FIG. 4 is a schematic cross-sectional view of the electrophoretic display device 101.
In the electrophoretic display device 101 according to this configuration example, the configurations of the partition walls 113 to 114 are different from those of the electrophoretic display device 11 shown in FIGS. 1 and 3, and the configurations of the other parts are the same.
FIG. 4 is a cross-sectional view of a cell partitioned by the partition wall 113, the partition wall 114, and another partition wall (not shown) when the partition wall 113 and the partition wall 114 facing each other are viewed from the side. In addition, an image of the flow of the dispersion is indicated by arrows.

  As shown in FIG. 4, in this configuration example, only one of the two partition walls 113 and 114 facing each other (in the example of FIG. 4, only the partition wall 114) is provided on the inner surface (the surface facing the inside of the cell). The pixel substrate 111 is inclined with respect to the normal direction (the normal direction of the pixel substrate). On the other hand (in the example of FIG. 4, the inner surface of the partition wall 113) is parallel to the normal direction.

As described above, in the electrophoretic display device 101 according to the present configuration example, the electrophoretic particles can be smoothly moved in the region (cell) partitioned by the partition walls 113 to 114 formed between the two substrates. can do. As a result, smooth image rewriting can be realized.
In this configuration example, a pressing imprint using a mold may be used. For example, by transferring with a mold, it is possible to easily create an inclined partition wall shape that is optimal for flow.

FIG. 5 is a cross-sectional view showing a schematic configuration example (first to third configuration example) for explaining the effect of the cross-sectional shape of the partition walls 163 to 164 of the electrophoretic display device 151.
The electrophoretic display device 151 includes a pixel substrate portion 161, a counter substrate portion 162, and partition walls 163 to 164.
Here, as in FIG. 3, FIG. 5 is a schematic cross-sectional view of the electrophoretic display device 151.
The electrophoretic display device 151 according to this configuration example is different in the configuration of the partition walls 163 to 164 from the electrophoretic display device 11 shown in FIGS. 1, 2, and 3, and the configuration of other parts is the same. It is.
FIG. 5 is a cross-sectional view of the partition 163, the partition 164, and another partition (not shown) viewed from the side of the partition 163 and the partition 164 facing each other. In addition, an image of the flow of the dispersion is indicated by arrows.

  As shown in FIG. 5, in this configuration example, only one of the two partition walls 163 and 164 facing each other (in the example of FIG. 5, only the partition wall 164) is formed on the inner surface (the surface facing the inside of the cell). The pixel substrate portion 161 is inclined with respect to the normal direction (the normal direction of the pixel substrate). In the present configuration example, the inclination is provided on the pixel substrate portion 161 side, and the inner surface is parallel to the normal direction on the counter substrate portion 162 side. In this configuration example, the dispersion liquid can be easily flowed by forming a curved shape on the inner surface of the partition wall 164 on the pixel substrate portion 161 side (in the example of FIG. 5, the bottom portion). The curved shape is, for example, an arc shape. As described above, in particular, the edge of the boundary between the partition wall (the partition wall 163 or the partition wall 164) and the substrate portion (the pixel substrate portion 161 or the counter substrate portion 162) is preferably a curved (curved) shape rather than a right angle. There is.

As described above, in the electrophoretic display device 151 according to this configuration example, the electrophoretic particles can be smoothly moved in the region (cell) defined by the partition walls 163 to 164 formed between the two substrates. can do. As a result, smooth image rewriting can be realized.
In this configuration example, a pressing imprint using a mold may be used. For example, by transferring with a mold, it is possible to easily create an inclined partition wall shape that is optimal for flow.

<Description of Display Surface Shape of Partition Wall of Electrophoretic Display Device>
With reference to FIGS. 6-10, the display surface shape of the partition of an electrophoretic display device is demonstrated.
Here, in order to explain the configuration and effect of the display surface shape of the partition wall of the electrophoretic display device, the cross-sectional shape of the partition wall is assumed to be a shape perpendicular to the substrate (pixel substrate and counter substrate).
In the present embodiment, a case where an electric field (vertical electric field) is applied between the pixel substrate and the counter substrate of the electrophoretic display device is shown.

In the present embodiment, a non-rotation symmetric shape (rotationally asymmetric shape) is used as the display surface shape of the partition walls of the electrophoretic display device. Specifically, when the display surface of the electrophoretic display device is viewed in plan, the display surface shape of the partition (here, the planar shape of one unit region (cell) formed by the partition) is rotationally asymmetric. .
Furthermore, when the display surface shape is a triangle, a shape that is not rotationally symmetric (a shape that is rotationally asymmetric) and a shape that is not line-symmetrical (a shape that is line-asymmetric) is used.
Here, as the shape other than the triangle, for example, a shape having four or more vertices (a polygon shape in which the number of vertices is a square or more) may be used.

FIG. 6 is a diagram illustrating a configuration example (second configuration example) according to the display surface shape of the partition wall of the electrophoretic display device.
In this configuration example, when viewed from a direction perpendicular to the display surface, the shape of the surface of one unit (one) region (cell) 201, 202 formed by the partition is a trapezoid. In the present embodiment, the display surface is a surface parallel to the counter substrate.
In this configuration example, when viewed from a direction perpendicular to the display surface, the shape of each region (cell) 201, 202 is the same trapezoid, and the plurality of regions (cells) 201, 202 are planar. Are lined up. In the example of FIG. 6, in two regions (cells) 201 and 202 (two trapezoids) that are adjacent in one direction, the longer side of one trapezoid (the longer of the two sides of different lengths facing each other) The two trapezoids are combined so that the other side of the other trapezoid and the shorter side of the other trapezoid (the shorter side of the two oppositely facing sides) are linear.
Various arrangements may be used as the arrangement in which the plurality of regions (cells) 201 and 202 are arranged in a plane.

FIG. 7 is a diagram illustrating a schematic configuration example (2-1 configuration example) for explaining the effect of the display surface shape of the partition walls of the electrophoretic display device.
Here, FIG. 7 is a schematic cross-sectional view of the electrophoretic display device 311 including a partition wall having the display surface shape shown in FIG. Further, FIG. 7 shows a display surface shape (in this example, a trapezoid) as a reference. In FIG. 7, the horizontal direction is enlarged to make it easier to see the image of the flow of the dispersion. The configuration of the electrophoretic display device 311 shown in FIG. 7 is the same as the configuration of the electrophoretic display device 11 shown in FIG. 1 except that the cross-sectional shape and display surface shape of the partition walls are different.

  In FIG. 7, between the pixel substrate portion 321 and the counter substrate portion 322, the partition wall 323 and the partition wall 324 that face each other with respect to cells partitioned by the partition wall 323, the partition wall 324, and another partition wall (not shown). Is a cross-sectional view as seen from the side. Further, in FIG. 7, an image of the flow of the dispersion is indicated by arrows.

In the cross-sectional view of FIG. 7, the partition 323 and the partition 324 are formed in parallel to the normal direction of the surface of the pixel substrate portion 321 (the normal direction of the surface of the pixel substrate (not shown)).
However, in this configuration example, the shape of the display surface formed by the partition walls 323 and 324 is a trapezoid shown in FIG. In the example of FIG. 7, the left partition 323 forms a long side of the trapezoid (the longer side of two opposing different lengths), and the right partition 324 forms the trapezoidal short side (opposite). The shorter side of the two sides having different lengths) is formed.

  In the configuration of the partition walls 323 and 324, taking the cross-sectional view of FIG. 7 as an example, in the electrophoretic layer, the dispersion medium (not shown), the first type of electrophoretic particles (not shown), the second type For electrophoretic particles (not shown), a unidirectional rotational flow immediately occurs and rectifies. In the example of FIG. 7, the flow of rotation in one direction is an upward flow from the bottom to the top on the partition wall 323 side, and a flow from the left to the right (on the side of the counter electrode (not shown)) The flow is dominant), and on the side of the partition wall 324, there is a downward flow from the top to the bottom (the downward flow is dominant).

  Thus, in the example of FIG. 7, the number of migrating particles moving from the side facing the display surface (pixel substrate side) to the display surface side (counter substrate side) is the location inside the region (cell). It depends on (position). In other words, when the migrating particles migrate upward, the dispersion medium also flows upward. However, since the display surface shape of the partition walls 323 to 324 is rotationally asymmetric, the number of migrating particles migrating upward in the cell depends on the location. Different. As a result, the dispersion medium has a speed in a predetermined plane direction. In the example of the cross-sectional view of FIG. 7, when an electric field is applied between the pixel electrode and the counter electrode, the dispersion medium does not antagonize force. Immediately flows so as to rotate smoothly. In the example of FIG. 7, since the amount of increase on the left side is larger than the amount of increase on the right side, a flow of right rotation occurs immediately and rectification occurs. Therefore, the migrating particles that rise in the ascending dispersion medium (in other words, the migrating particles that raise the dispersion medium) rise quickly, and the speed of the optical response is improved.

Specifically, in the example of FIG. 7, when the migrating particles migrate upward, the dispersion medium also flows upward. However, in the display surface shape, the left side width is less asymmetrical than the right side width, and thus the dispersion medium is dispersed. The medium will have a speed in the lateral direction (from left to right). For this reason, when the electrophoretic display device 311 is viewed in cross section as shown in FIG. 7, if an electric field is applied between the pixel electrode (not shown) and the counter electrode, the force is not antagonized and dispersed. The medium immediately flows so as to rotate smoothly. Therefore, the migrating particles that rise in the ascending dispersion medium (in other words, the migrating particles that raise the dispersion medium) rise quickly, and the response speed is improved.
Even when two or more types of migrating particles having different polarities (charge polarities) are present, each type of migrating particle determines the flow of the dispersion medium depending on the mobility, concentration, etc. Effects can be obtained.

  As described above, in this configuration example, the partition walls 323 to 324 are provided between the pair of substrates (the pixel substrate and the counter substrate), and the dispersion liquid is disposed in the region (cell) partitioned by the partition walls 323 to 324. In the electrophoretic display device 311, the dispersion liquid includes a dispersion medium and electrophoretic particles, and the partition walls 323 to 324 form a trapezoidal display surface shape.

In the electrophoretic display device 311 according to this configuration example, when the electrophoretic particles are moved in the vertical direction due to the trapezoidal display surface shape, the electrophoretic particles or the dispersion medium migrating in the vertical direction have a lateral speed. The electrophoretic particles or the dispersion medium can be moved in the lateral direction. As a result, the flow direction of the dispersion liquid (flow direction of the dispersion medium) arranged in the cells inside the partition walls 323 to 324 is changed during image rewriting (for example, when the voltage applied to the pixel electrode changes for each pixel). ) In the direction of flow (rectification) that rotates and moves in one direction. Therefore, for example, it is possible to improve the speed of the optical response compared to the conventional case, and it is possible to speed up the switching of the displayed image.
As described above, in the electrophoretic display device 311 according to this configuration example, the electrophoretic particles can be smoothly moved in the region (cell) partitioned by the partition walls 323 to 324 formed between the two substrates. be able to. As a result, smooth image rewriting can be realized.

FIG. 8 is a diagram illustrating a configuration example (second configuration example) according to the shape of the display surface of the partition wall of the electrophoretic display device.
In this configuration example, when viewed from a direction perpendicular to the display surface, the shape of the surface of one unit (one) region (cell) 221 and 222 formed by the partition walls is a triangle. In the present embodiment, the display surface is a surface parallel to the counter substrate.
In this configuration example, when viewed from a direction perpendicular to the display surface, the shape of each region (cell) 221 and 222 is the same triangle, and the plurality of regions (cells) 221 and 222 are planar. Are lined up. In the example of FIG. 8, in two adjacent regions (cells) 221 and 222 (two triangles), two triangles are combined so that the same sides face each other.
Various arrangements may be used as the arrangement in which the plurality of regions (cells) 221 and 222 are arranged in a plane.

FIG. 9 is a diagram illustrating a configuration example (second configuration example 2-3) related to the shape of the display surface of the partition wall of the electrophoretic display device.
In this configuration example, when viewed from a direction perpendicular to the display surface, the shape of the surface of one unit (one) region (cell) 241 and 242 formed by the partition walls is L-shaped. The width of one of the two rectangular portions of the L-shape is different from the width of the other. In the present embodiment, the display surface is a surface parallel to the counter substrate.
In this configuration example, the regions (cells) 241 and 242 have the same L shape when viewed from the direction perpendicular to the display surface, and the plurality of regions (cells) 241 and 242 are planar. Are listed. In the example of FIG. 9, two adjacent regions (cells) 241 and 242 (two L-shaped) are arranged so that the same side (only one side) inside the L-shape faces each other. L shape is combined.
Various arrangements may be used as an arrangement in which the plurality of regions (cells) 241 and 242 are arranged in a plane.

FIG. 10 is a diagram illustrating a configuration example (second configuration example 4) relating to a display surface shape of the partition wall of the electrophoretic display device.
In this configuration example, when viewed from the direction perpendicular to the display surface, the shape of the surface of one unit (one) region (cell) 261 formed by the partition walls is the four sides of the square. The one side of is a jagged shape. In the present embodiment, the display surface is a surface parallel to the counter substrate. As described above, in this configuration example, a part (here, the jagged portion) of the shape (here, the display surface shape) inside the region (cell) is different from the other parts.
Various arrangements may be used as the arrangement in which the plurality of regions (cells) 261 are arranged in a planar shape.

<Description of Combination of Cross Section Shape and Display Surface Shape of Partition Wall of Electrophoretic Display Device>
FIG. 11 is a diagram showing a configuration example of a region (cell) of the electrophoretic display device 411 according to one embodiment (first embodiment) of the present invention.
FIG. 11 illustrates a pixel substrate unit 421, a counter substrate unit 422, and partition walls 431 to 433 and 451 to 452 as components of the electrophoretic display device 411 according to the present embodiment.
Here, in the electrophoretic display device 411 according to the present embodiment, the cross-sectional shape of the partition wall shown in FIG. 1 (1-1 configuration example) and the display surface shape of the partition wall shown in FIG. The example of the configuration) is combined.

In the present embodiment, for example, an internal space defined by the partition wall 431, the partition wall 432, the partition wall 451, the partition wall 452, the pixel substrate unit 421, and the counter substrate unit 422 is one cell. On the surface of the pixel substrate portion 421, a plurality of cells having the same shape are provided side by side in two directions (horizontal direction and vertical direction) orthogonal to each other. In the present embodiment, one cell has a trapezoidal shape on the surface of the pixel substrate portion 421 and has a trapezoidal shape on the surface of the counter substrate portion 422.
Moreover, in this embodiment, each partition 431-433, 451-452 has plate shape. In addition, the inner surfaces (surfaces facing the inside of the cells) of the partition walls 431 to 433 have the same inclination with respect to a surface that includes an intersection line between the inner surface and the pixel substrate unit 421 and is parallel to the normal direction of the pixel substrate unit 421. Inclined at the same inclination angle in the direction. Further, the inner surfaces (surfaces facing the inside of the cells) of the partition walls 451 to 452 are surfaces parallel to the normal direction of the pixel substrate portion 421.
In this embodiment, the surface of the pixel substrate (not shown), the surface of the pixel substrate portion 421 (the surface of the insulating layer (not shown) in this embodiment), the surface of the counter substrate (not shown), The surface of the counter substrate portion 422 (the surface of the counter electrode (not shown) in this embodiment) is parallel to each other.

  In the present embodiment, the electrophoretic display device 411 displays an image on the counter substrate side (the side opposite to the pixel substrate). The surface on the counter substrate side is the display surface.

In the electrophoretic display device 411, a voltage is applied to each pixel electrode by a driving unit (not shown) and a voltage is applied to the counter electrode, so that each pixel electrode is connected between the pixel electrode and the counter electrode. Control the potential difference. Then, an electric field is generated in the normal direction of the pixel substrate due to the potential difference.
When the potential of the counter electrode is higher than that of the pixel electrode, for example, the first type of migrating particles (negatively charged white particles) move toward the counter electrode, and the second type of migrating particles (positively charged black particles). ) Moves to the pixel electrode side. Therefore, white is displayed.
On the other hand, when the potential of the counter electrode is lower than that of the pixel electrode, for example, the first type of migrating particles (negatively charged white particles) move to the pixel electrode side and the second type of migrating particles (positively charged particles). Black particles) move to the counter electrode side. Therefore, black is displayed.

  As described above, in the electrophoretic display device 411 according to the present embodiment, the effect obtained by the configuration of the cross-sectional shape of the partition shown in FIG. 1 (1-1 configuration example) and the partition shown in FIG. Both of the effects obtained by the configuration of the display surface shape (2-1 configuration example) can be realized. By combining both of these configurations, for example, partitioning by partition walls 431 to 433 and 451 to 452 formed between two substrates is more remarkable than when only one of the configurations is used. Smooth movement of the migrating particles can be realized in the formed region (cell).

  As an example, a partition wall 431 is formed by applying a sensitive resin to a substrate portion (in this embodiment, for example, an insulating layer provided on a pixel substrate), placing a mask, and exposing the substrate with light in an oblique direction. ˜433, 451˜452 can be formed. This formation method is easy to implement. Here, the azimuth angle of the exposure in the oblique direction may be arbitrary, for example, the direction along the sides of the predetermined partition walls 431 to 433, or the direction along the diagonal line. Good.

  In addition, in the configuration in which one pixel component (for example, a pixel electrode) is provided in one cell as in the present embodiment, high-speed response is possible and bleeding between pixels is prevented. It is possible. However, as another configuration example, two or more pixel components may be provided in one cell.

Here, the shape of the region (cell) may be various shapes. The number of partition walls that divide one cell may be various.
For example, in the present embodiment, the configuration of the cross-sectional shape (1-1 configuration example) of the partition wall illustrated in FIG. 1 is used, but other configurations may be used. As another configuration example, the configuration of the partition wall cross-section shape (1-2 configuration example) shown in FIG. 4 may be used as the partition wall cross-section shape, or the partition wall cross-section shape shown in FIG. The configuration of (1-3 configuration example) may be used, or other configurations may be used.
For example, in the present embodiment, the configuration of the display surface shape of the partition walls (second configuration example) shown in FIG. 6 is used, but other configurations may be used. As another configuration example, the configuration of the partition surface display surface shape (2-2 configuration example) shown in FIG. 8 may be used as the partition surface display surface shape, or the partition wall surface shown in FIG. The configuration of the display surface shape (2-3 configuration example) may be used, or the configuration of the partition display surface shape (2-4 configuration example) shown in FIG. 10 may be used. Alternatively, other configurations may be used.

Moreover, in this embodiment, the electrophoretic layer showed the structure containing a dispersion medium and two types of electrophoretic particles. As another configuration example, the number of types of electrophoretic particles may be one, or three or more. Moreover, the color of each electrophoretic particle may be arbitrary.
In this embodiment, the pixel substrate portion 421 is provided with an insulating layer. However, as another configuration example, the insulating layer may not be provided, and a layer of another material may be used instead of the insulating layer. It may be provided.

(Second Embodiment)
With reference to FIGS. 12-14, the example of a schematic structure of the electronic device which concerns on embodiment of this invention is shown. In the present embodiment, a specific example of an electronic apparatus to which the electrophoretic display device according to the above embodiment (the electrophoretic display device 421 according to the first embodiment) is applied will be described.

FIG. 12 is a diagram illustrating a schematic configuration example of an electronic apparatus according to an embodiment (first example of the second embodiment) of the present invention.
Specifically, FIG. 12 is a perspective view illustrating an electronic book 501 which is an example of an electronic device.
The electronic book 501 includes a book-shaped frame 511, a display unit 512 to which the electrophoretic display device according to the above embodiments is applied, and an operation unit 513.

FIG. 13 is a diagram illustrating a schematic configuration example of an electronic apparatus according to an embodiment of the present invention (second example of the second embodiment).
Specifically, FIG. 13 is a perspective view showing a wrist watch 551 which is an example of an electronic device.
The wristwatch 551 includes a display unit 561 to which the electrophoretic display device according to the above embodiment is applied.

FIG. 14 is a diagram illustrating a schematic configuration example of an electronic apparatus according to an embodiment (third example of the second embodiment) of the present invention.
Specifically, FIG. 14 is a perspective view illustrating an electronic paper 571 that is an example of an electronic apparatus.
The electronic paper 571 includes a main body portion 581 formed of a rewritable sheet having the same texture and flexibility as paper, and a display portion 582 to which the electrophoretic display device according to the above embodiments is applied.

  The electrophoretic display device according to the above embodiments may be applied to other various electronic devices, for example, display units for electronic devices such as mobile phones and portable audio devices, and business sheets such as manuals. It may be applied to textbooks, problem collections, information sheets, and the like.

  As described above, the electronic device according to the present embodiment can obtain the same effects as those of the electrophoretic display device according to the above embodiments.

(Various configuration examples of partition walls of electrophoretic display device)
In the following, first, the cross-sectional shape of the partition wall of the electrophoretic display device will be described, and then the display surface shape of the partition wall of the electrophoretic display device will be described.

<Various configuration examples of the cross-sectional shape of the partition wall of the electrophoretic display device>
Here, in order to describe the cross-sectional shape of the partition wall of the electrophoretic display device, the display surface shape of the partition wall is assumed to have a rotationally symmetric shape (here, a square shape).

The configuration of the partition wall of the electrophoretic display device may be exemplified in the above embodiment, or may be another configuration.
For example, the inner surfaces (surfaces facing the inside of the cells) of a plurality of partition walls that divide one region (cell) are the surfaces on the first substrate side, the inner surfaces of the first partition walls, And a shape for generating a unidirectional dispersion flow along the surface of the second substrate and the inner surface of the second partition.

In the electrophoretic display device according to one configuration example, a partition wall is provided between the first substrate and the second substrate, and the dispersion liquid is disposed in a region (cell) partitioned by the partition wall. The dispersion includes a dispersion medium and electrophoretic particles. The surface on the partition wall region (cell) side (inner surface of the partition wall) has an inclined portion that is inclined with respect to the normal direction of the first substrate. However, a predetermined configuration is excluded.
The predetermined configuration includes a plurality of sides formed by intersecting lines of the partition wall (cell) side surface (partition wall inner surface) and the first substrate side surface (first substrate portion surface). In all, the surface on the side of the partition wall region (cell) corresponding to each has a slope portion having the same slope direction and slope angle. That is, when all the partition walls partitioning the cells have the inclined portions having the same inclination direction and the same inclination angle, even if there is an inclination, the inclination of each side is equal when viewed from the inside of the cell and there is no difference. Therefore, the predetermined configuration is excluded.
In the electrophoretic display device according to this configuration example, it is possible to generate an asymmetric dispersion flow by the inclined portion.
Here, as an example, the first substrate is a pixel substrate, the first substrate portion is a pixel substrate portion, and the second substrate is a counter substrate. As another example, the first substrate is a counter substrate, the first substrate portion is a counter substrate portion, and the second substrate is a pixel substrate.

In the electrophoretic display device according to one configuration example, a partition wall is provided between the first substrate and the second substrate, and the dispersion liquid is disposed in a region (cell) partitioned by the partition wall. The dispersion includes a dispersion medium and electrophoretic particles. The surface on the partition wall region (cell) side (inner surface of the partition wall) has an inclined portion that is inclined with respect to the normal direction of the first substrate. The surface of the partition region (cell) side (inner surface of the partition wall) does not have symmetry when rotated about two or more different angles with respect to the normal axis of the first substrate. That is, for example, when the axis in the normal direction of the first substrate is taken at the center of the surface of the cell parallel to the first substrate (here, for example, a square), the first substrate around the axis When rotated by an angle (for example, 90 degrees or 45 degrees), the cells have the same shape (symmetry) and a second angle (for example, 180 degrees or 90 degrees, etc.) around the axis ) Except for cells that have the same shape (symmetry) when rotated only by ().
In the electrophoretic display device according to this configuration example, it is possible to generate an asymmetric dispersion flow by the inclined portion.
Here, as an example, the first substrate is a pixel substrate, the first substrate portion is a pixel substrate portion, and the second substrate is a counter substrate. As another example, the first substrate is a counter substrate, the first substrate portion is a counter substrate portion, and the second substrate is a pixel substrate.

In the electrophoretic display device according to one configuration example, a partition wall is provided between the first substrate and the second substrate, and the dispersion liquid is disposed in a region (cell) partitioned by the partition wall. The dispersion includes a dispersion medium and electrophoretic particles. The surface on the partition wall region (cell) side (inner surface of the partition wall) has an inclined portion that is inclined with respect to the normal direction of the first substrate. One of the plurality of sides formed by the intersection of the surface on the partition region (cell) side (inner surface of the partition wall) and the surface on the first substrate side (surface of the first substrate portion) The surface on the partition wall area (cell) side (inner surface of the partition wall) corresponding to only has an inclined portion. That is, for example, when a cell is partitioned by a plurality of partition walls, only one partition wall has an inclined portion.
In the electrophoretic display device according to this configuration example, it is possible to generate an asymmetric dispersion flow by the inclined portion.
Here, as an example, the first substrate is a pixel substrate, the first substrate portion is a pixel substrate portion, and the second substrate is a counter substrate. As another example, the first substrate is a counter substrate, the first substrate portion is a counter substrate portion, and the second substrate is a pixel substrate.

In the electrophoretic display device according to one configuration example, a partition wall is provided between the first substrate and the second substrate, and the dispersion liquid is disposed in a region (cell) partitioned by the partition wall. The dispersion includes a dispersion medium and electrophoretic particles. The surface on the partition wall region (cell) side (inner surface of the partition wall) has an inclined portion that is inclined with respect to the normal direction of the first substrate. However, among the plurality of sides formed by the intersections of the surface on the partition wall (cell) side (inner surface of the partition wall) and the surface on the first substrate side (surface of the first substrate portion), they are parallel to each other. The surface of the part corresponding to the two sides on the partition wall region (cell) side (inner surface of the partition wall) has a configuration in which both have inclined portions, and the normal line of the first substrate including the respective sides This is not a configuration in which the inclination direction of the inclined portion with respect to the plane parallel to the direction is opposite and the inclination angle is the same. That is, for example, the case where two opposing partition walls have inclined portions having the same inclination angle in opposite inclination directions is excluded.
In the electrophoretic display device according to this configuration example, it is possible to generate an asymmetric dispersion flow by the inclined portion.
Here, as an example, the first substrate is a pixel substrate, the first substrate portion is a pixel substrate portion, and the second substrate is a counter substrate. As another example, the first substrate is a counter substrate, the first substrate portion is a counter substrate portion, and the second substrate is a pixel substrate.

In the electrophoretic display device according to one configuration example, a partition wall is provided between the first substrate and the second substrate, and the dispersion liquid is disposed in a region (cell) partitioned by the partition wall. The dispersion includes a dispersion medium and electrophoretic particles. The surface on the partition wall region (cell) side (inner surface of the partition wall) has an inclined portion that is inclined with respect to the normal direction of the first substrate. In addition, among the plurality of sides formed by the intersecting lines of the surface on the partition wall (cell) side (inner surface of the partition wall) and the surface on the first substrate side (surface of the first substrate portion), they are parallel to each other. The surface on the partition wall region (cell) side of the portion corresponding to two sides has a configuration in which both have inclined portions, and is a surface parallel to the normal direction of the first substrate including the respective sides. The inclination direction and the inclination angle of the inclined portion with respect to are the same. That is, for example, the configuration shown in FIGS. 1, 2, and 3.
In the electrophoretic display device according to this configuration example, it is possible to generate an asymmetric dispersion flow by the inclined portion.
Here, as an example, the first substrate is a pixel substrate, the first substrate portion is a pixel substrate portion, and the second substrate is a counter substrate. As another example, the first substrate is a counter substrate, the first substrate portion is a counter substrate portion, and the second substrate is a pixel substrate.

As an example of the configuration, the plurality of sides described above form a polygonal side. That is, for example, the configuration shown in FIG. 1, FIG. 2 and FIG. 3, or FIG. 4 or FIG.
Thus, in the electrophoretic display device, a configuration in which the plurality of sides described above form polygonal sides may be used. With this configuration, in the electrophoretic display device, the region (cell) has a polygonal surface. Thereby, in the electrophoretic display device, when forming a region (cell) having a polygonal surface, it is possible to realize smooth movement of the electrophoretic particles in the region (cell).

As an example of the configuration, the surface (partition wall surface) on the partition wall region (cell) side of the portion corresponding to two sides parallel to each other among the plurality of sides described above is a flat surface. That is, for example, the configuration shown in FIG. 1, FIG. 2 and FIG. 3, or FIG.
As another configuration example, a surface (partition wall surface) on the partition wall region (cell) side of a portion corresponding to two parallel sides of the plurality of sides described above is a curved portion (an inclined portion). (Example). That is, for example, the configuration shown in FIG.

In the above description, the shape of the two partition walls facing each other (first substrate) as illustrated in FIGS. 3 to 5 among the plurality of partition walls partitioning one region (cell). A specific example in the case where the relationship of the shape including a three-dimensional arrangement with respect to the characteristic configuration is shown. As another configuration example, the relationship between the shapes of two partition walls that are not opposed to each other may be a characteristic configuration. The two partition walls may be, for example, two adjacent partition walls or two partition walls that are not adjacent to each other.
Each of the configurations illustrated in FIGS. 3 to 5 is an example in which a partition structure can be easily created, for example.

<Various configuration examples of the display surface shape of the partition wall of the electrophoretic display device>
Here, in order to describe the display surface shape of the partition wall of the electrophoretic display device, the cross-sectional shape of the partition wall is assumed to be a shape perpendicular to the substrate (pixel substrate and counter substrate).
As an example of the configuration, the shape of a plane parallel to the display surface of one unit region (cell) is a rotationally asymmetric shape that does not coincide with rotation at an arbitrary angle larger than 0 ° and smaller than 360 °.
As one configuration example, the shape of a surface parallel to the display surface of one unit region (cell) is a shape having four or more vertices.
As an example of the configuration, the shape of the surface parallel to the display surface of one unit region is a triangle. The shape is a rotationally asymmetric shape and a line asymmetric shape that is asymmetric with respect to an arbitrary straight line.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

11, 101, 151, 311, 411, 1001, electrophoretic display device, 21, 111, 161, 321, 421, 1011, pixel substrate portion, 22, 112, 162, 322, 422, 1012, counter substrate portion, 31 -33, 81-82, 113-114, 163-164, 323-324, 431-433, 451-453, 451-452, 1013-1014 ... partition walls, 41 ... dispersion medium, 42-43 ... electrophoretic particles, 61 ... pixel substrate, 62 ... Pixel electrode, 63 ... Insulating layer, 71 ... Counter substrate, 72 ... Counter electrode, 201-202, 221-222, 241-242, 261 ... Region (cell), 501 ... Electronic book, 511 ... Frame, 512, 561, 582 ... display unit, 513 ... operation unit, 551 ... wristwatch, 571 ... electronic paper, 581 ... main body unit

Claims (10)

A partition is provided between the first substrate and the second substrate, and the dispersion is disposed in a region partitioned by the partition,
The dispersion includes a dispersion medium and electrophoretic particles,
The shape of the surface parallel to the display surface of the unit in one unit is a rotationally asymmetric shape that does not coincide with rotation at an arbitrary angle larger than 0 ° and smaller than 360 °,
The surface of the partition on the side of the region has an inclined portion that is inclined with respect to the normal direction of the first substrate,
And the surface on the side of the region of the partition corresponding to all of the plurality of sides formed by the intersection lines of the surface on the side of the partition and the surface on the first substrate side. It is not a configuration having inclined portions with the same inclination direction and the same inclination angle,
Electrophoretic display device. The surface of the partition on the side of the region does not have symmetry when rotated about two or more different angles with respect to the normal axis of the first substrate.
The electrophoretic display device according to claim 1. A surface on the region side of the partition corresponding to only one of a plurality of sides formed by a line of intersection between the surface on the region side of the partition wall and the surface on the first substrate side. Having the inclined portion,
The electrophoretic display device according to claim 1. The shape of the surface parallel to the display surface of the region of the unit is a shape having four or more vertices.
The electrophoretic display device according to any one of claims 1 to 3. The shape of the surface parallel to the display surface of the unit of the unit is a triangle,
The shape is a rotationally asymmetric shape and a line asymmetric shape that is asymmetric with respect to an arbitrary straight line.
The electrophoretic display device according to any one of claims 1 to 3. Of the plurality of sides formed by intersecting lines between the region-side surface of the partition wall and the first substrate-side surface, portions of the region of the partition portion corresponding to two sides parallel to each other. Both side surfaces are configured to have the inclined portions, and the inclined directions of the inclined portions with respect to the plane parallel to the normal direction of the first substrate including the respective sides are opposite and the inclination angles are the same. Not a configuration,
The electrophoretic display device according to any one of claims 1 to 4. Of the plurality of sides, the surface on the region side of the partition corresponding to two sides parallel to each other is configured so that both have the inclined portion, and the first side including each side. The inclination direction and the inclination angle of the inclined portion with respect to a plane parallel to the normal direction of the substrate are the same configuration.
The electrophoretic display device according to claim 6. The surface on the side of the region of the partition corresponding to two sides parallel to each other among the plurality of sides is a plane.
The electrophoretic display device according to claim 6. The surface on the side of the region of the partition corresponding to two sides parallel to each other among the plurality of sides is a surface having a curved portion.
The electrophoretic display device according to claim 6.   An electronic apparatus comprising the electrophoretic display device according to any one of claims 1 to 9.

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